Dental injection gun

ABSTRACT

A dental injection gun is provided for injecting anesthetics into the peridental ligament and comprises a frame having a pistol grip portion carrying a sleeve holder to which is connected a syringe holder, a pusher rod being received in the sleeve holder and being provided with ridges acted upon by an apertured member when the latter is moved by an actuator to eject step-by-step an anesthesia from the gun occasioned by interaction of the apertured member with the ridges on the pusher rod.

United States Patent [191 Colombo DENTAL INJECTION GUN [76] Inventor:Americo Colombo, via Partigiani 24,

Como, Italy [22] Filed: Nov. 23, 1973 21 Appl. No.: 418,315

[30] Foreign Application Priority Data Nov. 25, 1972 Italy 7358/72 [52]U.S. Cl. 128/218 C; 222/309 [51] Int. Cl? A61M 5/315; G01F 11/06 [58]Field of Search 128/218 R, 215, 218 P, 128/218 C, 218 D, 234, 235, 218A, 236;

[56] References Cited UNITED STATES PATENTS 2,102,591 12/1937 Hagemeier222/386 X 2,316,095 4/1943 Mead, Jr 128/215 2,750,943 6/1956 Dann128/218 D [451 Sept. 16, 1975 2,892,457 6/1959 Sturtz 128/218 R3,110,310 11/1963 Cislak 128/218 C 3,141,583 7/1964 Mapel et a1 128/218D FOREIGN PATENTS OR APPLICATIONS 449,180 4/1968 Switzerland 128/218 RPrimary ExaminerRichard A. Gaudet Assistant ExaminerJ. C. McGowan 1ABSTRACT 4 Claims, 2 Drawing Figures PMEMEB SEP] 6 [975 mwH EQEEEEEEEEESiii m DENTAL INJECTION GUN This invention relates to a dental injectiongun.

Various authors have established. the value of intraligamentaryanesthesia in dentistry, but in practice it is not generally applied forlack of simple and effective instruments suitable for carrying it out.

It is therefore an object of the present invention to provide a dentalinjection gun into which a dental syringe can be inserted andconveniently actuated by a dentist to inject an anesthetic into theperidental ligament.

More particularly the invention provides a dental injection gun whichcomprises handle means similar to the handle of a gun and easily to begripped by one hand syringe holding means in the upper portion of saidhandle means, pusher means mounted on said handle means adjacent saidsyringe holding means rearwardly in the longitudinal extension thereoffor movement longitudinally of said syringe said pusher means beingarranged to act upon a piston in said syringe and control lever meanspivotally mounted on said handle means and pivotally connected to saidpusher means for imparting said longitudinal movement thereto.

A preferred embodiment of the invention will now be described withreference to the accompanying drawing in which FIG. 1 is a schematicside view of the dental injection gun; and FIG. 2 is an axial partcross-section taken along line IIII of FIG. 1.

Referring to the drawing, the dental injection gun shown therein has asyringe holder comprising a slotted sleeve 2 secured to a sleeve holder3 by means of a bay onet or screw coupling, and adapted to receive asyringe I. The sleeve holder 3 is an integral part of the frame of thegun, the frame being shaped to provide a pistol grip as hereinafter morefully disclosed. The syringe 1 has a piston (not shown) actuatable by apusher rod 6 provided with equally spaced transverse grooves definedbetween ridges on the rod and longitudinally shiftably mounted in aaxial bore provided in the sleeve holder 3 rearwardly in thelongitudinal extension of the syringe 1. Mounted on the pusher rod 6 isa lug 5 having a hole therein slightly larger than the diameter of thepusher rod 6 which extends through this hole. A double-armed bracket 9having an arm on either side of the pusher rod 6 has one end pivotallyconnected at 10 to a forked end 11 of a control lever 12 in the form ofa trigger which is mounted for swinging movement about a pivot 13. Theother end of the bracket 9 is pivotally connected at 7 to the bottom endof the lug 5. The rear end of the pusher rod 6 is provided with acountersunk knob 8 to prevent the lug 5 from slipping off the pusher rod6 and permit the lug 5 to be longitudinally adjusted in its position onthe pusher rod 6. A torsion spring 25 surrounds the pivot 7 and issupported with one end against the lug 5 and the other end against thebracket 9 whereby to normally incline the lug 5 in the direction shownin FIG. 1 in the non-actuated position of lever 12. A blade spring 14 isfixed laterally on the sleeve holder 3 and has a pin 15 at one endengaging on the ridges on the pusher rod 6. A similar blade spring isprovided on the other side of the sleeve holder 3 as shown in FIG. 2. Itwill be appreciated that by virtue of the torsion spring 25 and thepivotal mounting of lug 5 about pivot 7, the lug may be moved into anoppositely inclined position relative to that shown in FIG. 1 through anintermediate perpendicular position.

The pusher rod 6 with its control lever 12 is mounted on a handle 16 inthe form of a pistol grip. On the side adjacent the control lever 12 thehandle 16 has a projection 23 and therebelow a pair of recesses 24suitably shaped to receive a finger in each of them. An elongated leafSpring 17 is located within and extends longitudinally of the handle 16and is fixed at one end by means of a screw 18 to an interior lower wallof the handle 16. The other free end 19 of the leaf spring 17 isprovided with a hole through which extends a rod 20 provided with acollar 21 engaging the leaf spring 17 adjacent the hole at the free end19 thereof, the diameter of the collar 21 being larger than that of thehole in the leaf spring 17. The rod 20 is mounted within the handle 16but has a free end projecting therefrom and engaging the rear side ofthe control lever 12. So the leaf spring 17 urges the rod 20 against thecontrol lever 12 to keep the latter in its rest position in which thepusher rod 6 does not act upon the piston of the syringe l.

The operation'of the dental injection gun is as follows: I

The pusher rod 6 is pushed back as far as it will go by pulling the knob8 while keeping the lug 5 lightly pressed forward with a finger, thusallowing the lug to ride over the ridges of the pusher rod 6. In thisposition of the pusher rod 6'the syringe 1 can be easily inserted in thesyringe holder 2, 3 after the coupling 4 has been unscrewed or released.The syringe 1 complete with injection needle is then locked in thesyringe holder 2, 3

by means of the coupling 4. Then the gun is ready for the injectionoperation.

For the injection operation itself the injection gun is held by thehandle 16 in one hand with the thumb on one side thereof and the smallfinger and the ring finger on the other side in the recesses 24 belowthe projection 23 and the control lever 12 is pulled rearwardly by theforefinger and the middle fingerof the same hand placed in front of thelever 12 above the projection 23. Thereby the pusher rod 6 is movedstepwise forwardly and as the front end of the pusher rod 6 acts on therear of the piston in the syringe l, the syringe piston is movedforwardly and injects the anesthetic from the syringe 1 into theperidental ligament. Each actuation of the control lever 12 causes thepusher rod 6 to advance by one step the length of the steps beingdetermined by the length of travel of the lug 5. After each pull exertedon the control lever 12 the latter is returned to its forward positionby the leaf spring 17, the lug 5 riding over the ridges under the actionof the portion spring 25. In this manner a gradual injection operationis ensured. The blade springs 14 essentially have the purpose offrictionally resisting the movement of the pusher 6 by virtue ofengagement of pin 15 with the ridges on the pusher rod 6, whereas thetorsion spring surrounding the pivot 7 ensures that the lug 5 willengage the ridges of the pusher rod 6 during the forward movement of thecontrol lever. The slots in the sleeve 2 permit to observe the movementof the syringe piston. However, the end of the stroke of the syringepiston can also be checked by observing the degree of movement of theknob 8 relative to sleeve holder When it has thus been established thatthe syringe piston has reached the forward end of its stroke, theinjection operation is completed. The syringe is withdrawn from themouth of the patient and the syringe can be removed from the injectiongun by unlocking the coupling'4 as described above.

Although a preferred embodiment of the invention has been describedherein in detail and illustrated in the accompanying drawing it is to beunderstood that the invention is not limitedto this precise embodimentand that numerous changes and modifications'obvious to one skilled inthe art may be made therein without departing from the scope and spiritof the invention.

I claim: I

1. A dental injection gun comprising a frame having a portion thereofshaped to provide a pistol grip, an elongate sleeve holder integral withthe frame and being oriented substantially perpendicularly relativetothe pistol grip portion of the frame, an elongate sleeve adapted to holda syringe and being detachably connected to said sleeve holder for axialalignment therewith and extension therefrom, an elongate rod received.in said sleeve holder for movement relative thereto and being adaptedto act at one end thereof on a charge of anesthetic in said sleeve whenmoved in a predetermined direction relative to said sleeve holder, saidrod being formed with a plurality of ridges on its outer surface whichridges extend generally transverse .to the axis of the elongate rod andterminating in an enlarged head at that end of the rod opposite said oneend thereof, actuating means for actuating said rod and comprising leverarms one of which is a trigger arm extending in the general direction ofsaid pistol grip and being pivotally mounted to said frame with one endthereof proximate said rod and its opposite free end normally urged in adirection away from the pistol grip portion of the frame, said leverarms'including a double arm bracket pivotally mounted at one end thereofto said one end-of said trigger arm, a lug di sposed generallytransversely to the axis of the rod and being mounted to the oppositeend ofthe bracket for pivotal movement about an axis transverse to theaxis of the rod, said lug beingformed with a holeof a diameter slightlylarger than the largest diameter of the ridges on said rod, the latterpassing through said hole in said lug, and torsion spring means fornormally urging said lug into an inclined position ina directionopposite to the direction of advancement of said rod by said actuatingmeans and in which position of the lug the surface defining said holebeing-ingripping engagement with the ridges on the rod, said lug beingmovable into an oppositely inclined position through an intermediateperpendicular position.

2. The dental injection gun according to claim 1, wherein the springmeans biasing the aperturcd member is a torsion'spring. I

3. The dental injection gun according to claim 1, wherein the pistongrip is formed with a projection providing multiple finger engagingsurfaces.

4. The dental injection gun according to claim 1, there being includedmeans on the sleeve holder acting on said ridges for frictionallyholding the rod in the position in which it is moved

1. A dental injection gun comprising a frame having a portion thereofshaped to provide a pistol grip, an elongate sleeve holder integral withthe frame and being oriented substantially perpendicularly relative tothe pistol grip portion of the frame, an elongate sleeve adapted to holda syringe and being detachably connected to said sleeve holder for axialalignment therewith and extension therefrom, an elongate rod received insaid sleeve holder for movement relative thereto and being adapted toact at one end thereof on a charge of anesthetic in said sleeve whenmoved in a predetermined direction relative to said sleeve holder, saidrod being formed with a plurality of ridges on its outer surface whichridges extend generally transverse to the axis of the elongate rod andterminating in an enlarged head at that end of the rod opposite said oneend thereof, actuating means for actuating said rod and comprising leverarms one of which is a trigger arm extending in the general direction ofsaid pistol grip and being pivotally mounted to said frame with one endthereof proximate said rod and its opposite free end normally urged in adirection away from the pistol grip portion of the frame, said leverarms including a double arm bracket pivotally mounted at one end thereofto said one end of said trigger arm, a lug disposed generallytransversely to the axis of the rod and being mounted to the oppositeend of the bracket for pivotal movement about an axis transverse to theaxis of the rod, said lug being formed with a hole of a diameterslightly larger than the largest diameter of the ridges on said rod, thelatter passing through said hole in said lug, and torsion spring meansfor normally urging said lug into an inclined position in a directionopposite to the direction of advancement of said rod by said actuatingmeans and in which position of the lug the surface defining said holebeing in gripping engagement with the ridges on the rod, said lug beingmovable into an oppositely inclined position through an intermediateperpendicular position.
 2. The dental injection gun according to claim1, wherein the spring means biasing the apertured member is a torsionspring.
 3. The dental injection gun according to claim 1, wherein thepiston grip is formed with a projection providing multiple fingerengaging surfaces.
 4. The dental injection gun according to claim 1,there being included means on the sleeve holder acting on said ridgesfor frictionally holding the rod in the position in which it is moved.